Electric wire connector



Jan. 20, 1970 J. GLADER I 3,491,331

ELECTRIC WIRE CONNECTOR Filed May 12. 1967 INVENTOR. uA/v/Esr 94 4056,

United States Patent 3,491,331 ELECTRIC WIRE CONNECTOR James Glader, Mobridge, S. Dak. (8548 Rich Ave. S., Minneapolis, Minn. 55431) Filed May 12, 1967, Ser. No. 638,048 Int. Cl. H011- 7/06 US. Cl. 339270 2 Claims ABSTRACT OF THE DISCLOSURE A connection adapted to secure the bare end of a wire firmly in contact with a conductive surface with said surface being drawn into contact with said wire without substantial lateral displacement of said wire, said connection comprising mating frusto-conical sections with the wire clamped therebetween and with restraint against circumferential or lateral displacement of the wire relative to the mating frusto-conical surfaces.

It is an object of this invention to provide a simple solution a simple problem which, for whatever reason, the prior art has regarded as diificulty solveable. The foregoing sentence rather obviously is intended to anticipate the charge of obviousness on the general ground that while the complex may be obvious, the simple obviously is not.

The present invention has its basis in simplification of the prior art in which it would seem that heretofore complexity rather than simplicity has been the essence of patentability. The present invention utilizes what is among the simplest of geometric forms, the cone, and what is among the simplest sources of force multiplication, the screw.

If one disregards peril to life and limb, the establishment of a connection between one electrical circuit and another is of the utmost simplicity. One needs merely to establish contact between one connector and another than which nothing could be easier. When, however, such a connection is to be established and maintained over a period of time, certain other requisites must be taken into consideration. In any interface loss of voltage roughly is comparable to the interface loss of temperature in thermal-conductivity, that is to say: a firm connection in an electrical circuit is vastly preferable to a loose connection. In electrical circuits, for the most part, connections must be made between wires either to another wire or between a wire and a relatively fiat static surface such as a junction box, or an outlet or switch box.

The present invention deals with means for connecting wires which necessarily in the overwhelming bulk of cases are of cylindrical cross-section and of relatively small diameter. Such wires, when multi-stranded to an ultimate diameter between and A; of an inch, in practice present a considerable problem when brought into electrical contact by means of a conventional binding post. The binding post must rotate clockwise or counterclockwise, depending on the threads and usually rotates clockwise because that is how we are used to doing things. Any rotation between the conductor and the recipient surface tends to dissipate firm contact between a conductor and the recipient surface and this is multiply true if the conductor should be wound about a binding post in the opposite hand to that of the threads by which the binding post'engages the compressive member. The point just made will be appreciated by anyone who has performed the simple chore of rewiring a lamp socket.

The present invention involves not only the establishment of firm contact between a conductor and the recipient surface, but also the avoidance of forces tending laterally to distribute and thereby to isolate the strands 3,491,331 Patented Jan. 20, 1970 of a multi-strand conductor. In the drawings, the multistrand conductor is illustrated as a monofilament for simplicity of illustration, but the element of multi-strand conduction nevertheless is present and should be considered as integral with the annexed drawingss, in which:

FIGURE 1 is a plan view of a preferred form of device of the present invention;

FIGURE 2 is a side elevation, partly in section, of FIGURE 1, taken on the line 22 of FIGURE 1;

FIGURE 3 is a top plan view of a reversed form of the defice Of FIGURE 1;

FIGURE 4 is a section on the line 4-4 of FIGURE 3;

FIGURE 5 is a plan view of another alternative arrangement;

FIGURE 6 is a section taken on the line 6-6 of FIG- URE 5; and

FIGURE 7 is a view similar to FIGURE 6, but shows a reversal of parts.

Referring now to FIGURES 1 and 2, an outlet box, a switch box or equivalent alternative is indicated at 10. Pressed out of the outlet box or equivalent is a frustoconical member 14. A screw 16 enters the apex of the member 14 and engages a frusto-conical member 20 which by means of the threads 22 may be drawn up against the frusto-conical member 14, thereby clamping the wire 24 between the frusto-conical member 20 and the bulged-out member 14 of the plane surface 10.

The action and reaction of the screw 16 upon the frusto-conical member 20 against the outer frusto-conical member 14 involves a minimum of circumferential activity between the frusto-conical member 20 and the shell 14, hence, there is a minimum of lateral deviation of the wire normal to the axis of the screw 16.

A plurality of arcuate apertures 26 are formed in the frusto-conical protuberance 14 to receive a plurality of conductors 24. To establish connection, it is only necessary to peal away a portion of the insulation 28 to lay bare the conductor 24 and to insert the conductor 24 through the apertures 26 so that the cnductor 24 may be clamped between the frusto-conical member 20 and the frusto-conical protuberance 14 by the drawing action of the threads 22.

Referring now to FIGURES 3 and 4, there is shown a base plate 30 having a threaded aperture 32 mating with threads 34 of a screw 36. The screw 36 has a head 38 which bears on a frusto-conical member 40 which is loosely clamped between the head 38 and the screw 36 and a split ring 42. An internally frusto-conical externally cylindrical member 44 receives conductors 46 which have been stripped of insulation 48. The conductors 46 are clamped between the interior surface of the member 44 and the exterior surface of the member 40 by the drawing action of the threads 34 of the screw 36. Since the member 40 is freely rotatable on the screw 36, there is a minimal tendency for the member 40 to rotate relative to the screw 36 and therefore a minimum tendency for the member 40 to rotate relative to the member 44. As a result, if the conductors 46 are of the m-ulti-strand type, there is a minimal tendency toward displacements of the strands.

In FIGURES 5 and 6, there is shown a variation of the form described with reference to FIGURES 1 and 2, in which a frusto-conical member 14' is separately formed and welded at 50 to a base plate 10. An interior frustoconical member 20 engages the threads 22' of a screw 16'. The separate frusto-conical member 14' has conductor-receiving apertures 26 corresponding to the apertures 26, shown in FIGURE 1. The action, of course, is identical with that of the parts shownin FIGURES l and 2.

FIGURE 7 simply is a variation of FIGURES 3 and 4,

in which the externally cylindrical internally frustoconical member 44' is welded at 52 to a base sheet 30. A screw 36' has threads 34' engaging mating threads in the plate 30 and a split ring 42' engages a vfrusto-conical member 40 to hold the same loosely and rotatably between the head 38' and the split ring 42' of the screw 36'.

Of necessity, this invention has been described with reference to certain specific structural forms, as shown in the drawings. Various structural modifications, however, will occur to one skilled in the art and this invention is not to be limited to the precise details disclosed herein.

What is claimed is:

1. An electrical connector comprising: an electrically grounded planar base plate; a frusto-conical, hollow conductive member having its base integrally secured to said base plate and projecting therefrom; a solid frusto-conical core having an axial, threaded bore, said core being free within said member and loosely retained therein by said base plate; a screw entering the apex of said member and engaging said threaded bore, said screw having a head engaging the apex of said member to draw said core into said member.

2. The connector of claim 1, in which the hollow member has peripherally spacedapertures between its apex and base to provide locating means for wires to be placed between said member and said core.

References Cited UNITED STATES PATENTS 446,655 2/1891 Arld 339-270 X 1,389,929 9/1921 Barrow 339270 X 1,960,593 5/ 1934 Olson.

2,007,357 7/ 1935 Anderson et al. 339270 X 2,168,016 8/1939 Hanny. 2,278,986 4/1942 Gibbs 339-273 X 2,379,439 7/1945 Hotine 339270 X 2,547,176 4/1951 Salmons 339-270 X 1,328,784 1/1920 Benjamin et a1 339270 FOREIGN PATENTS 1,293,102 4/ 1962 France.

20 MARVIN A. CHAMPION, Primary Examiner JOSEPH H. MCGLY'NN, Assistant Examiner US. Cl. X.R. 3 39273 

